Furnace door

Abstract

The improved furnace of this invention may be used to produce heat by the burning of wood or other combustible matter. The furnace has a combustion chamber with a generally vertical axis and a chamber access door for loading combustible matter into the furnace. The access door in its normally closed position lies in a plane extending upwardly and outwardly from the axis of the chamber. A smoke limiting means which is positioned above the access door extends to the plane of closure of the door. This smoke limiting means limits the escape of smoke and other combustion products when the access door is open. The smoke limiting means may have a port for visually observing the interior of the chamber and for admitting a poker therein. An air injector extending through the door directs air to the burning material within the combustion chamber. The access door may have attached to it a grate extending into the chamber for holding the combustible material as it burns. The grate moves with the door making it easier to load fresh combustible matter onto the grate when the door is open and also shaking down previously burned material from the grate as the door is opened and closed. Finally, the furnace may be adapted with a latch means which automatically engages as the access door is opened but requires manual operation for release thereby preventing accidental closure of the door.

We claim: 
     
       1. A furnace for producing heat by the burning of wood and other solid combustible matter comprising: a combustion chamber generally adapted for containing within its interior the combustible matter, said chamber having a generally vertical axis and being defined by at least one wall, said wall having a chamber access door adapted to be moved from a normally closed position to an open position to allow combustible matter to be fed into said chamber, said door when in said closed position lying in a plane of closure extending upwardly and outwardly from said axis of said chamber, said door having in its normally closed position a center of gravity shifted outward relative to said wall of said chamber thereby reducing the force necessary to open said door;   a smoke limiting shelf associated with said chamber and said door for limiting the escape of smoke and other combustion products from said furnace when combustible material is burning within said chamber and said access door is in said open position, said smoke limiting shelf being positioned above said access door and extending outwardly and downwardly from said wall to said plane of closure of said access door;   a grate normally extending into said chamber for holding the combustible material as it burns, said grate being rigidly attached to said access door for movement with said door and at least partially out of said chamber as said door is opened for dislodging previously burned matter therefrom and for permitting easy access to said grate for loading combustible matter thereon; and air injector means extending through said access door for directing air from outside of said chamber to the area of said grate to support the burning of the combustible material lying thereon.   
     
     
       2. The furnace of claim 1 wherein said smoke limiting shelf includes a normally sealed port, said port when open permitting visual observation and poker access to the combustible matter contained within said combustion chamber. 
     
     
       3. The furnace of claim 1 wherein said air injector means includes damper means for regulating the quantity of air passing through said air injector means. 
     
     
       4. The furnace of claim 1 wherein said access door in its normally closed position and said grate attached thereto together have a center of gravity shifted outwardly relative to said wall of said chamber thereby reducing the force necessary to open said door. 
     
     
       5. The furnace of claim 1 including latch means adapted to automatically engage said door as it is opened to maintain said door in an open position but requiring manual release to permit said door to be closed thereby preventing accidental closure of said door. 
     
     
       6. The furnace of claim 5 wherein said latch means includes a slotted bracket attached to said door and a bar movably affixed to the furnace, said bar resting in a position in which it automatically engages the slots in said bracket as said door is opened, said bar being adapted to be disengaged from said slots by pivoting said bar clear of said bracket thereby permitting said door to be closed. 
     
     
       7. A furnace for producing heat by the burning of wood and other solid combustible matter comprising: a combustion chamber generally adapted for containing within its interior the combustible matter, said chamber having a generally vertical axis and being defined by at least one generally vertical wall, said wall having a chamber access door adapted to be moved from a normally closed position to an open position to allow combustible matter to be fed into said chamber, said door when in said closed position lying in a plane of closure extending upwardly and outwardly from said axis of said chamber, said door having in its normally closed position a center of gravity shifted outward relative to said wall of said chamber thereby reducing the force necessary to open said door;   smoke limiting means associated with said chamber and said door for limiting the escape of smoke and other combustion products from said furnace when combustible material is burning within said chamber and said access door is in said open position, said smoke limiting means being positioned above said access door and extending to said plane of closure of said access door;   a grate normally extending into said chamber for holding the combustible material as it burns, said grate being rigidly attached to said access door for movement with said door and at least partially out of said chamber as said door is opened for dislodging previously burned matter therefrom and for permitting easy access to said grate for loading combustible matter thereon; and,   air injector means extending through said access door for directing air from outside of said chamber to the area of said grate to support the burning of the combustible material lying thereon while preventing the escape of burning combustible matter through said access door as it is opened and closed.